The present invention relates to magnetic hard disk drives. More specifically, the present invention relates to a method of electrically connecting the actuator and micro-actuator to a control circuit.
In the art today, different methods are utilized to improve recording density in hard disk drives. FIG. 1 provides an illustration of a typical disk drive. The typical disk drive has a head gimbal assembly (HGA) configured to read from and write to a magnetic hard disk 101. The HGA and the magnetic hard disk 101 are mounted to the base 102 of a main board 103. The disk 101 is rotated relative to the base 102 by a spindle motor 104. The HGA typically includes an actuator arm 105 and a suspension 106. The HGA supports and positions a magnetic read/write slider 107 above the magnetic hard disk 101. The slider may contain transducers to perform the read/write function. The HGA is rotated relative to the base 102 along the axis of a pivot bearing assembly 108 by an actuator frame 109. The actuator frame 109 contains an actuator coil 110 driven by a magnet 111. A relay flexible printed circuit 112 connects a board unit 113 to the transducer of the magnetic read/write slider 107. The signal from the transducer is amplified by the preamplifier 114 before being transmitted along the relay flexible printed circuit.
FIG. 2 provides one illustration of an actuator as practiced in the prior art. The suspension 106, which supports the slider 107, may include a flexure 201 attached to a base plate 202 that suspends a load beam 203 coupled to the slider 107. The slider 107 may be electronically coupled by electrical traces 204 that run along the suspension 106 and actuator arm 105 to an actuator board 205. The actuator board 205 runs the signals from the slider 107 through a pre-amplifier 114 before sending them through the relay flexible printed circuit 112. The electrical traces 204 may be coupled to the actuator board 205 by a set of termination pads 206 at the end of the electrical traces 204.
FIG. 3 provides one illustration of the electrical connection between the slider 107 and the relay flexible printed circuit 112 as practiced in the prior art. The electrical trace 204 coupled to the suspension 106 may electrically connect the slider 107 to the termination pads 206. The termination pads 206 may be coupled to a set of contact pads 301 on the actuator board 205. The signal is then sent through a pre-amplifier to the relay flexible printed circuit 112.
In order to carry out previous methods of establishing an electrical connection, the flex cable on the suspension must be aligned properly to the pads of the actuator board 205. If soldering is used to connect the pads, the solder bump must be preliminarily formed on the pads for solder bonding. Laser or ultrasonic bonding can be prohibitively expensive and time consuming due to the necessary calibration work.